Presenter report:
Lang, Irene Marthe (Austria)
Bosentan for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) and post-pulmonary endarterectomy pulmonary hypertension: a subgroup analysis of the randomised, placebo-controlled trial - BENEFiT.
Irene Lang, Medical University of Vienna, Vienna, Austria.
Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the leading causes of pulmonary hypertension (PH). It is characterised by chronic organised thromboemboli that obstruct the pulmonary vessels, promoting increased pulmonary vascular resistance (PVR), progressive PH and right heart failure.
Pulmonary endarterectomy (PEA) involves the surgical removal of major-vessel pulmonary vascular occlusions. Since PEA is potentially curative, it is the treatment of choice for CTEPH patients with operable disease. Although a consensus definition for operability is lacking, between 10–50% of patients present an unacceptable operative risk due to inaccessible material, mismatch between haemodynamic compromise and accessible occlusions, distal arteriopathy and/or co-morbid diseases. Moreover, PH may persist or reappear in an estimated 10-20% of operated patients. Persistent PH is the most important determinant of post-PEA outcome. Therefore, other treatment options are required for these patients. An important prognostic factor in CTEPH is the degree of haemodynamic disturbance that is a factor guiding treatment for patients with CTEPH, and is an important consideration when determining operability.
In the randomized, placebo-controlled BENEFIT trial, 157 patients were randomised to bosentan or placebo. Of these, 113 were inoperable (bosentan, n = 55; placebo, n = 58) and 44 patients were post-PEA (bosentan, n = 22; placebo, n = 22). Significant reductions in PVR were observed in both groups. The mean treatment effect was –17.5% [–27.0, –6.7] in the inoperable group and –32.5% [–44.4, –18.1] in the post-PEA group. Mean 6min walk distance was unchanged in both groups. Improvements in the Borg dyspnea index were observed in the inoperable group (mean treatment effect: –0.8 [–1.6, –0.1]), but not in the post-PEA group (0.1 [-0.9, 1.2]). In the inoperable and post-PEA groups, respectively, there were improvements in favor of bosentan on mean cardiac index (0.31 [0.12, 0.50] and 0.25 [–0.08, 0.57] L/min/m2), mean mPAP (–1.0 [–3.9, 1.9] and –6.4 [–11.2, –1.7] mmHg) and mean NT-pro-BNP (–654 [–1170, –138] and –526 [–1054, 2] ng/L).
The BENEFiT study results suggest that bosentan improves haemodynamics in both patients with inoperable CTEPH and those with persistent or recurrent PH after PEA.